Low frequency ( Utility Power line carrier systems have long been a favorite at many utilities because it allows them to reliably move data over an infrastructure that they control. Many technologies are capable of performing multiple applications. For example, a communication system bought initially for automatic meter reading can sometimes also be used for load control or for demand response applications. PLC is one of the technologies used in the automatic meter reading industry. Both one-way and two-way systems have been successfully used for decades. Interest in this application has grown substantially in recent history -- not so much because there is an interest in automating a manual process, but because there is an interest in obtaining fresh data from all metered points in order to better control and operate the system. PLC is one of the technologies being used in Advanced Metering Infrastructure (AMI) systems. In a one-way (inbound only) system, readings "bubble up" from end devices (i.e. meters), through the communication infrastructure, to a "master station" which publishes the readings. A one-way system might be lower-cost than a two-way system, but also is difficult to reconfigure should the operating environment change. In a two-way system (supporting both outbound and inbound), commands can be broadcast out from the master station to end devices (meters) -- allowing for reconfiguration of the network, or to obtain readings, or to convey messages, etc. The device at the end of the network may then respond (inbound) with a message that carries the desired value. Outbound messages injected at a utility substation will propagate to all points downstream. This type of broadcast allows the communication system to simultaneously reach many thousands of devices -- all of which are known to have power, and have been previously identified as candidates for load shed. PLC also may be a component of a smart power grid. [edit] Standards organizations Several competing standards are evolving including the HomePlug Powerline Alliance, Universal Powerline Association, European Telecommunications Standards Institute, and the IEEE. It is unclear which standard will come out ahead. X10 is a de facto standard also used by RadioShack's Plug'n'Power system. In 2006 the ITU-T began work on G.hn, a new home networking standard for operation over powerline, coax and phonewires. * Consumer Electronics Powerline Communications Alliance (CEPCA) (Sony, Mitsubishi and Panasonic) is developing a standard to realize coexistence between various Powerline technologies, available today. [3] * IEEE produces standards for several types of power line communications systems. o IEEE 643-2004 "Guide for Power-Line Carrier Applications" is a standard for communication over the transmission line network (above 69kV). o IEEE P1675 "Standard for Broadband over Power Line Hardware" is a working group working on hardware installation and safety issues. o IEEE P1775 "Powerline Communication Equipment - Electromagnetic Compatibility (EMC) Requirements - Testing and Measurement Methods" is a working group focused on PLC equipment, electromagnetic compatibility requirements, and testing and measurement methods. o IEEE P1901 "IEEE P1901 Draft Standard for Broadband over Power Line Networks: Medium Access Control and Physical Layer Specifications" is a working group for delivering broadband over power lines. The aim is to define medium access control and physical layer specifications for all classes of BPL devices - from long distance connections to those within subscriber premises. Many companies and standard bodies are participating in the developing IEEE P1901 standard including HomePlug Powerline Alliance, UPA, CEPCA and OPERA; this means a good chance for a unified power line communication standard in the future. Launch is expected in 2008. o IEEE BPL Study Group — "Standardization of Broadband Over Power Line Technologies" drove the creation of the BPL related P1901 working groups. It still meets time-to-time looking to create new working groups if needed. website * LonWorks powerline communication is used worldwide, for example for Home Automation, Street Lighting, Energy Management and Utility Metering. Related standards can be found on [4] * OPERA (Open PLC European Research Alliance) is a R&D Project with funding from the European Commission. It aims to improve the existing systems, develop PLC service, and standardise systems. * POWERNET is a R&D Project with funding from the European Commission. It aims to develop and validate a ‘plug and play’ Cognitive Broadband over Power Lines (CBPL) communications equipment that meet the regulatory requirements concerning electro-magnetic radiations and can deliver high data rates while using with low transmit power spectral density and working at low signal to noise ratio. border="0" alt="Hit Counters"> Web Site Hit Counter

Utility

Power line carrier systems have long been a favorite at many utilities because it allows them to reliably move data over an infrastructure that they control. Many technologies are capable of performing multiple applications. For example, a communication system bought initially for automatic meter reading can sometimes also be used for load control or for demand response applications.

PLC is one of the technologies used in the automatic meter reading industry. Both one-way and two-way systems have been successfully used for decades. Interest in this application has grown substantially in recent history -- not so much because there is an interest in automating a manual process, but because there is an interest in obtaining fresh data from all metered points in order to better control and operate the system. PLC is one of the technologies being used in Advanced Metering Infrastructure (AMI) systems.

In a one-way (inbound only) system, readings "bubble up" from end devices (i.e. meters), through the communication infrastructure, to a "master station" which publishes the readings. A one-way system might be lower-cost than a two-way system, but also is difficult to reconfigure should the operating environment change.

In a two-way system (supporting both outbound and inbound), commands can be broadcast out from the master station to end devices (meters) -- allowing for reconfiguration of the network, or to obtain readings, or to convey messages, etc. The device at the end of the network may then respond (inbound) with a message that carries the desired value. Outbound messages injected at a utility substation will propagate to all points downstream. This type of broadcast allows the communication system to simultaneously reach many thousands of devices -- all of which are known to have power, and have been previously identified as candidates for load shed. PLC also may be a component of a smart power grid.

[edit] Standards organizations

Several competing standards are evolving including the HomePlug Powerline Alliance, Universal Powerline Association, European Telecommunications Standards Institute, and the IEEE. It is unclear which standard will come out ahead. X10 is a de facto standard also used by RadioShack's Plug'n'Power system. In 2006 the ITU-T began work on G.hn, a new home networking standard for operation over powerline, coax and phonewires.

* Consumer Electronics Powerline Communications Alliance (CEPCA) (Sony, Mitsubishi and Panasonic) is developing a standard to realize coexistence between various Powerline technologies, available today. [3]

* IEEE produces standards for several types of power line communications systems.
o IEEE 643-2004 "Guide for Power-Line Carrier Applications" is a standard for communication over the transmission line network (above 69kV).
o IEEE P1675 "Standard for Broadband over Power Line Hardware" is a working group working on hardware installation and safety issues.
o IEEE P1775 "Powerline Communication Equipment - Electromagnetic Compatibility (EMC) Requirements - Testing and Measurement Methods" is a working group focused on PLC equipment, electromagnetic compatibility requirements, and testing and measurement methods.
o IEEE P1901 "IEEE P1901 Draft Standard for Broadband over Power Line Networks: Medium Access Control and Physical Layer Specifications" is a working group for delivering broadband over power lines. The aim is to define medium access control and physical layer specifications for all classes of BPL devices - from long distance connections to those within subscriber premises. Many companies and standard bodies are participating in the developing IEEE P1901 standard including HomePlug Powerline Alliance, UPA, CEPCA and OPERA; this means a good chance for a unified power line communication standard in the future. Launch is expected in 2008.
o IEEE BPL Study Group — "Standardization of Broadband Over Power Line Technologies" drove the creation of the BPL related P1901 working groups. It still meets time-to-time looking to create new working groups if needed. website

* LonWorks powerline communication is used worldwide, for example for Home Automation, Street Lighting, Energy Management and Utility Metering. Related standards can be found on [4]
* OPERA (Open PLC European Research Alliance) is a R&D Project with funding from the European Commission. It aims to improve the existing systems, develop PLC service, and standardise systems.
* POWERNET is a R&D Project with funding from the European Commission. It aims to develop and validate a ‘plug and play’ Cognitive Broadband over Power Lines (CBPL) communications equipment that meet the regulatory requirements concerning electro-magnetic radiations and can deliver high data rates while using with low transmit power spectral density and working at low signal to noise ratio.



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